Compact image capture assembly using multiple lenses and image sensors to provide an extended zoom range

ABSTRACT

An optical image capture assembly for use in an electronic camera includes a first image sensor for generating a first sensor output; a first lens for forming a first image of the scene on the first image sensor; a second image sensor for generating a second sensor output; and a zoom lens for forming a second image of the scene on the second image sensor. The camera is contained within an enclosure and, in one variation of the assembly, either the first lens or the zoom lens (or both) forms its image through a folded optical system in which an optical path between the lens and its respective image sensor is folded at an angle in order to conserve space within the enclosure.

FIELD OF THE INVENTION

The present invention relates to a digital camera that produces digitalimage files and, more particularly, to a digital camera that usesmultiple lenses and image sensors to provide an extended zoom range.

BACKGROUND OF THE INVENTION

Currently, most digital cameras use a zoom lens and a single color imagesensor to capture still and motion images. The captured images are thendigitally processed to produce digital image files, which are stored ina digital memory in the camera. The digital image files can then betransferred to a computer, displayed, and shared via the Internet. Thedigital camera can be included as part of a mobile telephone, to form aso-called “camera phone”. The camera phone can transmit the digitalimage files to another camera phone, or to service providers, via amobile telephone network.

Small camera size and a large “optical zoom range” are two veryimportant features of digital cameras. Users prefer to have a large zoomrange (e.g. 5:1 or greater) rather than a limited zoom range (e.g. 3:1or smaller). Unfortunately, providing a large zoom range lens, withoutsacrificing the quality of the captured images, increases the size ofthe digital camera. Large zoom range lenses are also more costly. Thus,there are fundamental trade-offs between small camera size, large zoomrange, and low camera cost which must be made when designing a digitalcamera. With higher cost cameras, such as single lens reflex cameras,these problems are sometimes addressed by using multiple interchangeablezoom lenses, such as two 3:1 zoom lenses, e.g., a 28-70 mm zoom and a70-210 zoom. Such an option, which has its own problems in userinconvenience, is nonetheless not available for low cost digitalcameras.

The prior art of most interest can be separated into two categories:image capture systems that use multiple lenses, usually two, having thesame focal length and image capture systems that utilize multiplelenses, also usually two, having different focal lengths.

Addressing the first category, some digital cameras use multiple imagesensors to form a color image. In most cameras of this type, a singlelens is used to provide an image of the scene, which is then separatedinto multiple colors by a prism beam splitter. Multiple monochrome imagesensors are used to capture red, green, and blue color separationimages. However, as disclosed in U.S. Pat. No. 6,611,289, entitled“Digital Cameras Using Multiple Sensors with Multiple Lenses” and issuedAug. 26, 2003 in the name of Yu et al., it is possible to use multipleimage sensors and multiple lenses to provide color separation. However,this patent disclosure teaches that the lenses all have the same focallength, and are all used together, in order to simultaneously capturethe different color components of the image.

Some digital imaging systems also use multiple image sensors andmultiple lenses to capture different portions of the digital image. Sucha system is disclosed in U.S. Published Patent Application No.US20020163582 A1, entitled “Self-calibrating, Digital, Large FormatCamera with Single or Multiple Detector Arrays and Single or MultipleOptical Systems” and published Nov. 7, 2002 in the names of Gruber etal. In one embodiment disclosed in this published patent application, alarge format digital camera exposes multiple detector arrays usingmultiple lens systems to acquire sub-images of overlapping sub-areas oflarge area objects. The sub-images are stitched together to form a largeformat digital macro-image. However, all of the lenses have the samefocal length, and all are used simultaneously to capture the differentsub-areas of the image.

Stereo film cameras and stereo electronic cameras are known in the priorart. These cameras typically have two horizontally separated lenses ofthe same focal length, which focus two slightly different images of thescene onto two image sensors or two frames of film. Such a system isdisclosed in commonly assigned U.S. Pat. No. 4,989,078, entitled “StillVideo Camera for Recording. Stereo Images on a Video Disk” and issued onJan. 21, 1991 in the name of K. Bradley Paxton. The two images provide aso-called “stereo pair”, which simulates the slightly differentperspectives that a person's left and right eyes would see when viewingthe scene. In the aforementioned patent disclosure, the two lenses aredesigned to provide the same magnification, and both are used tosimultaneously capture the left and right eye images on a pair of imagesensors in order to achieve a stereo effect.

Film cameras that use multiple lenses to capture multiple images at thesame time are also known in the prior art. For example, some instantfilm cameras used to produce identification pictures can capture foursmall images simultaneously on the same piece of instant film. The fourlenses in these cameras provide the same magnification, and all are usedto simultaneously capture the four images.

According to the second category of prior art, film cameras that includetwo or more lenses to provide two or more different focal lengths arealso known in the prior art. For example, such cameras can use twodifferent fixed focal length lenses which are slid in front of the samefilm plane. This provides an inexpensive “two-position zoom” capability,that is, two fixed focal length lenses that provide, e.g., the wideangle and telephoto angle settings of a corresponding zoom lens. Inanother example, in U.S. Pat. No. 4,097,882, entitled “Multiple LensCamera Having Lens-position Controlled Focal-length Adjustment” andissued Jun. 27, 1978 in the name of Engelsmann, a “110” size pocket filmcamera has a carrier mounting three or more lenses of different focallengths that can be selectively moved transverse to the optical axis ofthe camera so as to place any one of the lenses in an operating positionrelative to a film plane.

Digital cameras that include two lenses to provide two different focallengths are also known in the prior art. A lens turret is popularly usedto obtain multiple focal lengths in a camera. However, in the case of adigital still camera or especially in the case of mobile phone digitalcamera, lens modules are required to be extremely small due to thelimited space for the lens module. U.S. Pat. No. 6,804,460, entitled“Lens Turret with Back Focal Length Adjustment” and issued Oct. 12, 2004in the names of Oshima et al., describes a lens turret that is said tobe extremely compact and flat in size and suitable for digital stillcameras and mobile phone digital cameras. The lens turret is rotatablearound an axis and has a wide-angle lens and a telephoto-angle lensmounted thereon, and a driving mechanism rotates the lens turret so thatone of the lenses can be set at a picture taking position opposite animage sensor. By means of back focal length adjustment, the position ofthe lens with the shorter focal length can be fixed on the lens turretat the same level thereon as the lens with the longer focal length.

It is also known to use a two lens arrangement in a film scanner, wheretwo lenses with different combinations of focal lengths are used tocapture variable sized images. For instance, in commonly assigned U.S.Pat. No. 5,929,903, entitled “Multiposition Lens Mechanism for aScanner” and issued Jul. 27, 1999 in the name of R. H. Kiesow, aremovable digital camera, which is tethered to a computer, is supportedin a housing in a film scanner in the optical path of a multipositionlens assembly having a single focal length lens and a zoom lens. Thelens assembly positions the lenses in the optical path of the camera forscanning different sized images, e.g., two or more film format sizes.However, these cameras, both film and digital, that use multiple focallength lenses share the characteristic of using only a single “sensor”,that is, a single film or a single electronic image sensor.

In U.S. Pat. No. 6,288,742, entitled “Video Camera Including MultipleImage Sensors” and issued Sep. 11, 2001 in the names of Ansari et el., adigital motion camera useful in teleconferencing includes two lenses andtwo image sensors. As disclosed in this patent, the first lens is an 8mm fixed focus lens for providing a relatively wide-angle view of a roomand the second lens is a 16 mm lens with manual focus control forproviding high resolution document transmission capability. The firstlens is oriented for a room view of a conference participant to provideface-to-face communication during a videotelephone conference, and thesecond lens is oriented at a substantial angle to the first lens forviewing a document, e.g., on a table. During a videotelephoneconference, such a camera permits fast switching between an image of theroom as seen through the first lens or an image of a document as seenthrough the second lens, without the need for expensive and tediouslyslow moving pan/tilt stages and/or a plurality of complete camera units.Another camera, the Sanyo S750 UMTS cellphone camera, has a similar kindof dual imaging capability, where an inwardly facing VGA imager capturesan image of the caller using the cellphone while an outwardly facing 1megapixel imager captures an image of a scene that the caller is lookingat. Such cameras, however, are not useful in the environment of thepresent invention because the lenses are not collecting images from thesame scene.

In U.S. Pat. No. 4,199,785, entitled “Electronic Zoom Feature” andissued Apr. 22, 1980 in the name of McCullough et al., a televisionsystem employs two (or more) fixed focal length vidicon cameras, onecamera with a wide angle field of view and the other camera with anarrow angle field of view, and an electronic zoom feature for zoomingbetween the two fields of view. The cameras are boresighted such thatthe field of view of the smaller field camera is within, and usuallycentered in the field of view of the larger field camera. The “zoom” isaccomplished by manipulating the scan generators of the two cameras andexpanding the central portion of the display with the image from thesmaller field camera as the zoom amount is progressively increased. Thissystem, of course, is an alternative to a single optical zoom lens,whose usage the patent disclosure discourages as they (optical zooms)are lower quality, more expensive and mechanically more complex thanfixed focal length lenses. However, the inherent drawback of anelectronic zoom is also low quality since the resolution of theelectronic zoom feature ordinarily is limited by the number of scanlines available for zooming. Consequently, this patent disclosure isdevoted to controlling the scan lines of the two vidicon cameras so asto be able to zoom without an effective loss of resolution.

In U.S. Pat. No. 5,051,830, entitled “Dual Lens System for ElectronicCamera” and issued Sep. 24, 1991 in the name of Hoessle, a double focallength electronic camera (used on board a guided missile) includes asingle lens system component having a short focal length sectionintegrated into the center of a surrounding lens section having a longfocal length, where each focal length section has its own dedicatedpicture array sensor. Here too, this lens system is a substitute for asingle motor driven zoom, which the disclosure denigrates because ofsize, expense, heaviness, inherent complexity; furthermore, an opticalzoom is “which is important—much too slow with respect to its use” (col.2, line 1 of the Hoessle patent).

None of these prior art systems, and especially the multifocal lengthprior art systems, provide a sufficiently compact, low cost, large zoomrange optical system for a small, lightweight and relatively inexpensiveconsumer digital camera. As especially pointed out in the aforementionedHoessle patent, it is additionally desirable to avoid the slowness sotypical of zoom usage and to be able to traverse a large zoom rangequickly. What is therefore needed is a digital camera that provides arapidly-operating extended zoom range without unduly increasing the sizeor cost of the digital camera.

SUMMARY OF THE INVENTION

The object of this invention is to provide an extended zoom range in adigital camera without unduly increasing the size or cost of the camera.

Another object of this invention is to provide an extended optical zoomrange in a digital camera by means of a plurality of separate lenses andcorresponding image sensors.

Another object of this invention is to provide an extended optical zoomrange in a digital camera by means of a compact image capture assemblyincluding a plurality of separate lenses and corresponding imagesensors.

The present invention is directed to overcoming one or more of theproblems set forth above. Briefly summarized, the invention comprises anoptical image capture assembly for use in an electronic camera, wherethe assembly comprises: a first image sensor for generating a firstsensor output; a first lens for forming a first image of the scene onthe first image sensor; a second image sensor for generating a secondsensor output; and a zoom lens for forming a second image of the sceneon the second image sensor, wherein the zoom lens is adjustable betweena minimum focal length and a maximum focal length to provide the secondimage. In one variation of this embodiment, the camera is containedwithin an enclosure and at least one of the first lens and the zoom lensforms its image through a folded optical system in which an optical pathbetween the lens and its respective image sensor is folded at an anglein order to conserve space within the enclosure.

These various aspects of the invention provide significant technicaladvantages. By providing a plurality of optical image capture modalitieswithin a digital camera, wherein each modality includes a lens-sensorcombination with a distinctive different focal length or combination offocal lengths (i.e., a zoom), the conflicted requirements (namely, largesize, high cost and compromised optical quality) engendered by digitalcamera consumer desire for a large zoom ratio, e.g., 10:1, can beaccomplished in a smaller scale space at lower cost with higher qualityoptical results than heretofore achieved.

These and other aspects, objects, features and advantages of the presentinvention will be more clearly understood and appreciated from a reviewof the following detailed description of the preferred embodiments andappended claims, and by reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a block diagram of a first embodiment of a digital camerausing a fixed focal length, wide-angle lens with a first image sensor,and a zoom lens with a second image sensor.

FIGS. 2A and 2B are two perspective views of the digital camera shown inFIG. 1.

FIG. 3 depicts a flow diagram showing a method for capturing digitalimages using the digital camera shown in FIG. 1.

FIG. 4 depicts a block diagram of a second embodiment of a digitalcamera using a first zoom lens with a first image sensor, and a secondzoom lens with a second image sensor.

FIGS. 5A and 5B are two perspective views of the digital camera shown inFIG. 4.

FIG. 6 depicts a flow diagram showing a method for capturing digitalimages using the digital camera shown in FIG. 4.

FIG. 7 depicts a block diagram of a third embodiment of a digital camerausing a first zoom lens with a first image sensor, a second zoom lenswith a second image sensor and a fixed focal length lens with a thirdimage sensor.

FIGS. 8A and 8B are two perspective views of the digital camera shown inFIG. 7.

FIG. 9 depicts a flow diagram showing a method for capturing digitalimages using the digital camera shown in FIG. 7.

FIGS. 10A, 10B, 10C, 10D, 10E and 10F diagram the optical layout ofseveral embodiments of the image capture assembly used in the camerasshown in FIGS. 1, 4, 7, 19 and 21 according to the invention.

FIG. 11 is a frontal view of a digital camera employing two imagecapture assemblies, one fixed focal length and the other zoom, of thetype shown in FIGS. 10A-10F.

FIG. 12 is a top view of the digital camera shown in FIG. 11.

FIG. 13 is a side view of the digital camera shown in FIG. 11.

FIGS. 14A and 14B are two views of a digital camera employing two imagecapture assemblies, both zoom, of the type shown in FIGS. 10A-10F.

FIGS. 15A and 15B are two views of a digital camera employing threeimage capture assemblies of the type shown in FIGS. 10A-10F.

FIGS. 16A and 16B show two views of the optical relay subassembly shownin the various embodiments of FIGS. 10A-10F for supporting a fixed focallength lens in relation to an image sensor along a folded optical pathaccording to the invention.

FIG. 17 shows the optical relay subassembly shown in the variousembodiments of FIGS. 10A-10F for supporting a zoom lens in relation toan image sensor along a folded optical path according to the invention.

FIGS. 18A and 18B show two imagers with different panoramic aspectratios and the effect obtained by changing the aspect ratio.

FIG. 19 depicts a block diagram of a further embodiment of a digitalcamera using a first fixed focal length lens with a first sensor, asecond fixed focal length lens with a second sensor, and a third fixedfocal length lens with a third sensor.

FIG. 20 depicts a flow diagram showing a method for capturing digitalimages using the digital camera shown in FIG. 19.

FIG. 21 depicts a block diagram of a further embodiment of a digitalcamera using a first lens with a first sensor having pixels of one size.e.g., three micron pixels, and a second lens with a second sensor havingpixels of another size, e.g., five micron pixels.

FIG. 22 is a diagram useful for explaining an express zooming feature.

FIGS. 23A and 23B are perspective views of the front and back of a cellphone including a camera with multiple lenses and multiple sensors.

FIGS. 24A and 24B are two views of the image capture assembly used inthe cell phone shown in FIGS. 23A and 23B.

DETAILED DESCRIPTION OF THE INVENTION

Because digital cameras employing imaging devices and related circuitryfor signal processing are well known, the present description will bedirected in particular to elements forming part of, or cooperating moredirectly with, apparatus in accordance with the present invention.Elements not specifically shown or described herein may be selected fromthose known in the art. Certain aspects of the embodiments to bedescribed may be provided in software. Given the system as shown anddescribed according to the invention in the following materials,software not specifically shown, described or suggested herein that isuseful for implementation of the invention is conventional and withinthe ordinary skill in such arts.

Each of the several embodiments of the present invention include animage capture assembly having multiple lenses and multiple image sensorsmounted within a digital camera in order to provide an extended zoomrange. This can reduce the cost and size of the camera, and improve itsoptical performance, compared with a camera having a single sensor and alarge range zoom lens (e.g. having a 10:1 zoom range). While not in anexactly coaxial arrangement with respect to each other, the multiplelenses and sensors are generally aligned with respect to each other soas to be viewing substantially the same object, albeit with differentfields of view. Each image capture assembly comprises two or moreoptical relay subassemblies having a lens and an image sensor disposedat opposing ends thereof and a folded optical path for directing thelight from the lens to the sensor. This configuration can further reducethe size of the optical components, thereby enabling the design andmanufacture of a very thin and compact camera. While the folded opticsare used in many of the preferred embodiments, a folded optical path isnot generally necessary for practice of the invention. This isparticularly true for the wide angle optical subassemblies since thefocal length of such wide angle lenses is very short to begin with.Also, the size of the sensor, and consequently the size of the imagethat must be produced to fill the sensor, may be small enough to reducethe focal length to an acceptable front-to-back dimension—even fornormal and short telephoto focal lengths.

In each embodiment, the camera includes a control element for selectingeither the first sensor output from the first image sensor or a sensoroutput from one of the other image sensors, thereby providing a selectedsensor output that may be provided to a processing section in the camerafor producing an output image. Moreover, each embodiment includes sometype of user control that allows a user to select a focal length, eitherdirectly or via some marking (e.g., “panoramic” or “portrait”)indicative of a focal length; the aforementioned control element is thenresponsive to the user control for selecting a corresponding sensoroutput. In some embodiments, a single “zoom lens” user control is used,e.g., where the “wide” setting selects a wide angle fixed focal lengthlens and the “tele” setting(s) select various positions of a zoom lens.The user control output is then provided to the control element, whichselects the image sensor that is used to produce the output image. Whenthe selected sensor is for the zoom lens, the user control (or thecontrol element) also enables the zoom and focus motors for the zoomlens to drive the zoom lens to the selected focal length. In addition,digital zooming may be used to zoom “up” from the wide angle setting tothe minimum focal length setting of the zoom lens. All this, of course,may be transparent to the user, who simply manipulates the “zoom lens”user control between the “wide” and “tele” settings.

Referring first to FIGS. 10A-10F, several diagrams are shown of theoptical layout of several embodiments of an image capture assembly 1,which is included within the various embodiments of a digital camera(which will be described later). These diagrams include the opticalrelay subassemblies 1 a, 1 b and 1 c containing the aforementionedfolded optical elements. In each of the FIGS. 10A-10F, a circle 1 ddelineates an optical profile of a front surface of a digital camerathrough which the respective lenses protrude. The optical relaysubassemblies 1 a, 1 b and 1 c are folded behind the lenses and, as willbe described, covered by the front surface of the camera.

In a first embodiment of the present invention, a digital camera employsa first fixed focal length wide angle lens 2 with a first image sensor12, and a zoom lens 3 with a second image sensor 14. In the firstembodiment as shown in FIG. 10A, an image capture assembly 1 includesthe first lens 2 and the first image sensor 12 mounted at opposing endsof a first optical relay subassembly 1 a having a folded optical patharranged between the first image sensor 12 and the lens 2. The firstlens 2, which preferably is a fixed focal length wide angle lens, formsa first image of a scene on the first image sensor 12. The image captureassembly 1 also includes the zoom lens 3 and the second image sensor 14mounted at opposing ends of a second optical relay subassembly 1 bhaving a folded optical path arranged between the second image sensor 14and the zoom lens 3. The zoom lens 3, which has a range of focal lengthsadjustable between a minimum focal length and a maximum focal length,forms a second image of the scene on the second image sensor 14. In thisembodiment, the first lens 2 is a wide angle lens having a focal lengthless, and preferably substantially less, than the minimum focal lengthof the zoom lens 3.

In a second embodiment of the present invention, a digital cameraemploys a first zoom lens 3 with an image sensor 14, and a second zoomlens 4 with an image sensor 16. In the second embodiment as shown inFIG. 10B, the image sensor 14 will be characterized as the first imagesensor 14 and the image sensor 16 will be characterized as the secondimage sensor 16. Accordingly, the image capture assembly 1 includes thefirst zoom lens 3 and the first image sensor 14 mounted at opposing endsof a first optical relay subassembly 1b having a folded optical patharranged between the first image sensor 14 and the first zoom lens 3.The first zoom lens 3, which has a range of focal lengths adjustablebetween a minimum focal length and a maximum focal length, forms a firstimage of the scene on the first image sensor 14. The image captureassembly 1 also includes the second zoom lens 4 and the second imagesensor 16 mounted at opposing ends of a second optical relay subassembly1 c having a folded optical path arranged between the second imagesensor 16 and the zoom lens 4. The zoom lens 4, which has a range offocal lengths adjustable between a minimum focal length and a maximumfocal length, forms a second image of the scene on the second imagesensor 16. In this embodiment, the maximum focal length of the firstzoom lens 3 is less than or equal to the minimum focal length of thesecond zoom lens 4.

In a third embodiment of the present invention, the digital cameraemploys a first zoom lens 3 with an image sensor 14, a second zoom lens4 with an image sensor 16 and a fixed focal length, wide angle lens 2with an image sensor 12. In the third embodiment as shown in FIG. 10C,the image sensor 14 will be characterized as the first image sensor 14,the image sensor 16 will be characterized as the second image sensor 16,and the image sensor 12 will be characterized as the third image sensor.Accordingly, the first zoom lens 3 forms a first image of the scene onthe first image sensor 14, and the second zoom lens 4 forms a secondimage of the scene on the second image sensor 16, similarly to what isshown and described in FIG. 10B. In addition, a third lens, the fixedfocal length lens 2, and the third image sensor 12 are mounted atopposing ends of a third optical relay subassembly 1 a having a foldedoptical path arranged between the third image sensor 12 and the thirdlens 2. In this embodiment, the third lens 2 preferably is a fixed focallength wide angle lens having a focal length less, and preferablysubstantially less, than the minimum focal length of the first zoom lens3, and the maximum focal length of the first zoom lens 3 is less than orequal to the minimum focal length of the second zoom lens 4.

In a fourth embodiment of the invention, the digital camera employs afirst fixed focal length lens 2 a with a first image sensor 12 a, and asecond fixed focal length lens 2 b with a second image sensor 12 b. Inthe fourth embodiment as shown in FIG. 10D, an image capture assembly 1includes the first fixed focal length lens 2 a and the first imagesensor 12 a mounted at opposing ends of a first optical relaysubassembly 1 a(1) having a folded optical path arranged between thefirst image sensor 12 a and the first fixed focal length lens 2 a. Theimage capture assembly 1 also includes the second fixed focal lengthlens 2 b and the second image sensor 1 2 b mounted at opposing ends of asecond optical relay subassembly 1 a(2) having a folded optical patharranged between the second image sensor 12 b and the second fixed focallength lens 2 b. In this embodiment, the first fixed focal length lens 2a is preferably a wide angle lens and the second fixed focal lens 2 b isa telephoto lens.

In a fifth embodiment of the present invention, the digital cameraemploys a first fixed focal length lens 2 a with a first image sensor 12a, a second fixed focal length lens 2 b with a second image sensor 12 band a third fixed focal length lens 2 c with a third image sensor 12 c.In the fifth embodiment as shown in FIG. 10E, the first lens 2 a and thefirst image sensor 12 a are mounted at opposing ends of a first opticalrelay subassembly 1 a(1) having a folded optical path arranged betweenthe first image sensor 12 a and the first lens 2 a. The first lens 2 a,which preferably is a fixed focal length ultra wide angle lens, forms afirst image of the scene on the first image sensor 12 a. The second lens2 b and the second image sensor 12 b are mounted at opposing ends of asecond optical relay subassembly 1 a(2) having a folded optical patharranged between the second image sensor 12 b and the second lens 2 b.The second lens 2 b, which preferably is a fixed focal length mediumangle lens, forms a second image of the scene on the second image sensor12 b. The third lens 2 c and the third image sensor 12 c are mounted atopposing ends of a third optical relay subassembly 1 a(3) having afolded optical path arranged between the third image sensor 12 c and thethird lens 2 c. The third lens 2 c, which preferably is a fixed focallength narrow angle (telephoto) lens, forms a third image of the sceneon the third image sensor 12 c.

In a sixth embodiment of the present invention, the digital cameraemploys a first fixed focal length lens 2 a with a first image sensor 12a, a second fixed focal length lens 2 b with a second image sensor 12 b,a third fixed focal length lens 2 c with a third image sensor 12 c, anda fourth fixed focal lens 2 d with a fourth image sensor 12 d. In thesixth embodiment as shown in FIG. 10F, the first lens 2 a and the firstimage sensor 12 a are mounted at opposing ends of a first optical relaysubassembly 1 a(1) having a folded optical path arranged between thefirst image sensor 12 a and the first lens 2 a. The first lens 2 a,which preferably is a fixed focal length ultra wide angle lens, forms afirst image of the scene on the first image sensor 12 a. The second lens2 b and the second image sensor 12 b are mounted at opposing ends of asecond optical relay subassembly 1 a(2) having a folded optical patharranged between the second image sensor 12 b and the second lens 2 b.The second lens 2 b, which preferably is a fixed focal length mediumangle lens, forms a second image of the scene on the second image sensor12 b. The third lens 2 c and the third image sensor 12 c are mounted atopposing ends of a third optical relay subassembly 1 a(3) having afolded optical path arranged between the third image sensor 12 c and thethird lens 2 c. The third lens 2 c, which preferably is a fixed focallength narrow angle (telephoto) lens, forms a third image of the sceneon the third image sensor 12 c. The fourth lens 2 d and the fourth imagesensor 12 d are mounted at opposing ends of a fourth optical relaysubassembly 1 a(4) having a folded optical path arranged between thefourth image sensor 12 d and the fourth lens 2 d. The fourth lens 2 d,which preferably is a fixed focal length very narrow angle (longtelephoto) lens, forms a fourth image of the scene on the fourth imagesensor 12 d.

These embodiments may clearly be carried as far as possible—i.e., morethan four lenses, four sensors and four optical relay subassemblies—aslong as their arrangement is practically possible within the spatialconfines of the digital camera.

FIG. 11 provides a spatial layout of a digital camera, showing how thevarious components described in FIG. 10A fits within the confined spaceof the digital camera 10A. For example, FIGS. 11 and 12 show how theimage capture assembly 1 is arranged within the width-wise dimension 201of a digital camera 10A for the first embodiment shown in FIG. 10A. FIG.11 is a frontal view of the digital camera 10A showing how the fixedfocal length lens subassembly 1 a and the zoom lens subassembly 1 b arepositioned to one side of the lenses 2 and 3 beneath an electronic flash48. A battery compartment 204 is located on the other side of the lenses2 and 3. FIG. 12 is a top view of the digital camera 10A taken alonglines 12-12 in FIG. 11, and further shows the location of a removablememory card 54 and a color LCD image display 70. FIG. 13 is a side viewof the digital camera 10A taken along the lines 13-13 in FIG. 12, andfurther shows the vertical spacing of the fixed focal length lenssubassembly 1 a, the zoom lens subassembly 1 b, and the flash 48. It isparticularly noteworthy that the folded optics employed in thesubassemblies 1 a and 1 b enable the image capture assembly 1 to fitwithin a compact front to rear dimension 210 of the camera 10A. It isalso noteworthy that the embodiment of FIG. 10D, employing two fixedfocal length lens subassemblies 1 a(1) and 1 a(2), could be substitutedinto the arrangement shown in FIG. 1, thereby enabling a camera witheven a lesser width-wise dimension 201.

FIGS. 14A, 14B, and 14C show an arrangement of the components in thesecond embodiment shown in FIG. 10B within the digital camera 10B, whereFIG. 14B is a top view taken along the lines 14B-14B in FIG. 14A, andFIG. 14C is a side view taken along the lines 14C-14C in FIG. 14B. Notethat, because of the larger size of the second zoom subassembly 1 c, thespatial relationship of the components has been rearranged. The batterycompartment 204 has now been moved under the flash 48, thereby freeingup more room on the opposite side of the lenses 3 and 4 for the foldedoptics. Similarly, FIGS. 15A, 15B and 15C show an arrangement of thecomponents in the third embodiment shown in FIG. 1C, where FIG. 15B is atop view taken along the lines 15B-15B in FIG. 15A, and FIG. 15C is aside view taken along the lines 15C-15C in FIG. 15B. It should be clearfrom these illustrations that the front-to-back folding of the opticalsystems offers significant advantages over the prior art, and over evensuch an optical system as shown in the aforementioned Hoessle reference(U.S. Pat. No. 5,051,830), which shows two optical paths integrated intoone system. The narrow front-to-back dimension 210 produces apocket-sized camera, and in the context of this invention, apocket-sized camera with zoom, or zoom-like, features.

In each of the above embodiments, the image capture assembly may beintegrated into the manufacture of the digital camera or it may standalone as a fungible component that is, e.g., separately manufactured andsupplied to a camera manufacturer for insertion into the camera. Theimage capture assembly may further include a control section for drivingthe sensors and selecting either the first sensor output from the firstimage sensor or a sensor output from one of the other image sensors. Inaddition, in some embodiments the sensors in the image capture assemblymay be positioned next to each other on a common circuit board assembly,or may be packaged in a common integrated circuit package, and thelenses in the image capture assembly may be provided in a common lensassembly that mounts onto the circuit board or the integrated circuitpackage. In some preferred embodiments, the separate imaging arrays arepart of the same CCD or CMOS integrated circuit, and the two lenses areassembled together and aligned with the sensor package.

Moreover, in the foregoing embodiments providing a plurality of three ormore image sensors for generating three or more sensor outputs, and aplurality of three or more lenses for forming a corresponding three ormore images of the scene on the corresponding three or more imagesensors, the lenses employed may be provided in different spatialarrangements within the front optical profile 1 d of the digital camera.Where three lenses are employed, the three lenses may be provided withinthe optical profile 1 d on the camera in a triangular arrangement, asshown in FIG. 10C or 10E. Where four lenses are employed, the fourlenses may be provided within the optical profile 1 d on the camera in arectangular arrangement as shown in FIG. 10F.

Furthermore, in each of the embodiments, when the fixed, or maximum,focal length of one lens is less than the minimum focal length of thenext greater focal length lens, there is a focal length gap left betweenthe two lenses. In that case, the processing section in the camera mayinclude an electronic zooming capability for electronically zooming overat least a portion of the focal length gap. Consequently, if a single“zoom lens” user control is used, a transition between some settings ofthe user control will cause a zoom lens to move to a particular opticalzoom position, while a transition between other settings of the usercontrol will cause the processor to digitally zoom up from an opticalimage output of the wide angle lens. For example, where the electroniccamera provides a zoom setting over a range including a wide angleoptical focal length and a group of optical focal lengths provided by atleast one tele zoom lens, at least some of the intervening focal lengthsin the gap between the wide angle focal length and the zoom focallengths of the tele zoom are provided by electronically zooming up froman image captured at the wide angle optical focal length. Furthermore,the wide angle optical focal length that is being zoomed can be providedby the maximum focal length of another (wide angle) zoom lens.

FIGS. 16A and 16B show two views of the optical relay subassembly lashown in FIGS. 10A, and 10C-10F for supporting a fixed focal length lens2 in relation to an image sensor 12 along a folded optical pathaccording to the invention. FIG. 16A shows a lens barrel 6 a forsupporting the outer objective of the fixed focal length lens 2, theimage sensor 12 and associated relay lens components 7 a in an opticalpath that is folded by a mirror prism 8 a. In addition, the lens barrel6 a supports an aperture shutter assembly 9 a in the optical path. FIG.16B is a view taken along the line 16B-16B in FIG. 16A, showing anappearance of the optical subassembly 1 a from the face of the camera(as shown generally in FIG. 10A). FIG. 17 shows the optical relaysubassembly 1 b (or 1 c) shown in FIGS. 10A, 10B and 10C for supportinga zoom lens 3 (or 4) in relation to an image sensor 14 (or 16) along afolded optical path according to the invention. FIG. 17 shows a fixture6 b for supporting the outer objective of the zoom lens 3 (or 4), thesecond image sensor 14 (or third image sensor 16), and movable relay(zoom) lens components 7 b in an optical path that is folded by a mirrorprism 8 b. In addition, the fixture 6 b supports an aperture shutterassembly 9 b in the optical path. FIG. 17 also shows the zoom and focusmotors 5 a for controlling the movement of the lens components 7 b.

FIG. 1 depicts a block diagram of a digital camera 10A, which utilizesthe first embodiment of the present invention. The digital camera 10A isa portable battery operated device, small enough to be easily handheldby a user when capturing and reviewing images. In the preferredembodiment, the digital camera 10A produces still digital images thatare stored on a removable memory card 54. The digital camera may producemotion digital images, either exclusively or in addition to the stillimages, that are also stored on the memory card 54.

The digital camera 10A includes the aforementioned image captureassembly 1 described in FIGS. 10A and 11, comprising a fixed focallength lens 2 that focuses an image of a scene (not shown) onto a firstimage sensor 12, and a zoom lens 3 which focuses an image of the sceneonto a second image sensor 14. The image capture assembly 1 provides afirst image output 12 e from the first image sensor 12 and a secondimage output 14 e from the second image sensor 14. In one preferredembodiment, the images sensors 12 and 14 are identical in size, both asto aspect ratio and pixel size, the lens 2 is an ultra-wide angle lenswith a “35 mm film equivalent focal length” of 22 mm (written as 22 mmequiv., where 22 mm is the focal length of a 35 mm photographic filmcamera that provides the same field of view as the fixed lens 2 providesto the image sensor 12, as defined in the ANSI/13A IT10.7000-2004standard available from the American National Standards Institute, Inc.,New York, N.Y.), and the zoom lens 3 is a 3:1 zoom lens having a 38mm-114 mm equiv. focal length range.

The 35 mm film equivalent focal length (f.l.) can be calculated usingthe formula:35 mm-equiv. f.l=(actual lens f.l. (in mm)×43.27 mm)/(diagonal sensorfocal plane distance (in mm)).For example, if the image sensor uses a ½″ type optical format, it has afocal plane of 6.4 mm (width)×4.8 mm (height), with a diagonal distanceof 8.0 mm. If this type of image sensor is used with a lens having anactual focal length of 4.0 mm, the 35 mm equiv. focal length is 22 mm.

Because the focal length of the fixed lens 2 generates an ultra-wideangle field of view, e.g., 22 mm equiv., it has a fixed focus set to adistance near the lens hyperfocal distance of 8 feet, so that objectsfrom 4 feet to infinity are in focus. Therefore, fixed lens 2 does notneed to include a focus adjustment. The fixed focal length lens 2includes an adjustable aperture and shutter assembly 9 a (as shown FIGS.16A and 16B) to control the exposure of the image sensor 12. The zoomlens 3 is controlled by zoom and focus motors 5 a and an adjustableaperture and shutter assembly 9 b (as shown in FIGS. 17A and 17B) tocontrol the exposure of the image sensor.

In a preferred embodiment, the image sensors 12 and 14 are single-chipcolor Megapixel CCD sensors, using the well-known Bayer color filterpattern to capture color images. The image sensors 12 and 14 can have,for example, a 4:3 image aspect ratio and a total of 3.1 effectivemegapixels (million pixels), with 2048 active columns of pixels×1536active rows of pixels. The image sensors 12 and 14 can use a ½″ typeoptical format, so that each pixel is approximately 3.1 microns tall by3.1 microns wide. A control processor and timing generator 40 controlsthe first image sensor 12 by supplying signals to clock drivers 13, andcontrols the second image sensor 14 by supplying signals to clockdrivers 15.

The control processor and timing generator 40 also controls the zoom andfocus motors 5 a, and a flash 48 for emitting light to illuminate thescene. The control processor and timing generator 40 also receivessignals from automatic focus and automatic exposure detectors 46. In analternative embodiment, instead of using the automatic focus andautomatic exposure detectors 46, the image sensor 14 could be used toprovide exposure detection and “through-the-lens” autofocus, asdescribed in commonly-assigned U.S. Pat. No. 5,668,597, which isentitled “Electronic Camera with Rapid Automatic Focus of an Image upona Progressive Scan Image Sensor” and which issued Sep. 26, 1997 in thenames of Kenneth A. Parulski, Masaki Izumi, Seiichi Mizukoshi andNobuyuki Mori, and which is incorporated herein by reference. Usercontrols 42 are used to control the operation of the digital camera 10A.

The analog output signal 12 e from the first image sensor 12 isamplified by a first analog signal processor (ASP 1) 22 and provided toa first input of a control element 34, e.g., an analog multiplexercontrol element. The analog output signal 14 e from the second imagesensor 14 is amplified by a second analog signal processor (ASP 2) 24and provided to a second input of the control element 34, that is, theanalog multiplexer control element. The function of the control element34 is to select either the first sensor output 12 e from the first imagesensor 12 or the second sensor output 14 e from the second image sensor14, thereby providing a selected sensor output from the image captureassembly 1.

The control processor and timing generator 40 controls the analogmultiplexer control element 34 in order to provide the output of eitherthe (ASP 1) 22 or the (ASP 2) 24 to an analog-to-digital (A/D) convertercircuit 36. The digital data provided by the A/D converter 36 is storedin a DRAM buffer memory 38 and subsequently processed by an imageprocessor 50. The processing performed by the image processor 50 iscontrolled by firmware stored in a firmware memory 58, which can beflash EPROM memory. The processor 50 processes the input digital imagefile, which is buffered in a RAM memory 56 during the processing stage.

In an alternative embodiment (not shown), two A/D converter circuits areconnected to the outputs of ASP 1 (22) and ASP 2 (24) and the analog mux34 is not used. Instead, a digital multiplexer is used to select whichone of the outputs of the two A/D converters is connected to the DRAMbuffer memory 38.

The processed digital image file is provided to a memory card interface52, which stores the digital image file on the removable memory card 54.Removable memory cards 54 are one type of removable digital imagestorage medium, and are available in several different physical formats.For example, the removable memory card 54 can include (withoutlimitation) memory cards adapted to well-known formats, such as theCompact Flash, SmartMedia, MemoryStick, MMC, SD, or XD memory cardformats. Other types of removable digital image storage media, such asmagnetic hard drives, magnetic tape, or optical disks, can alternativelybe used to store the still and motion digital images. Alternatively, thedigital camera 10A can use internal non-volatile memory (not shown),such as internal Flash EPROM memory to store the processed digital imagefiles. In such an embodiment, the memory card interface 52 and theremovable memory card 54 are not needed.

The image processor 50 performs various housekeeping and imageprocessing functions, including color interpolation followed by colorand tone correction, in order to produce rendered sRGB image data. Therendered sRGB image data is then JPEG compressed and stored as a JPEGimage file on the removable memory card 54. The rendered sRGB image datamay also be provided to a host PC 66 via a host interface 62communicating over a suitable interconnection, such as a SCSIconnection, a USB connection or a Firewire connection. The JPEG fileuses the so-called “Exif” image format defined in “Digital Still CameraImage File Format (Exif)” version 2.1, July 1998 by the JapanElectronics Industries Development Association (JEIDA), Tokyo, Japan.This format includes an Exif application segment that stores particularimage metadata, including the date/time the image was captured, as wellas the lens f/number and other camera settings.

It should be noted that the image processor 50, while typically aprogrammable image processor, can alternatively be a hard-wired customintegrated circuit (IC) processor, a general purpose microprocessor, ora combination of hard-wired custom IC and programmable processors.

The image processor 50 also creates a low-resolution “thumbnail” sizeimage, which can be created as described in commonly-assigned U.S. Pat.No. 5,164,831, entitled “Electronic Still Camera Providing Multi-FormatStorage Of Full And Reduced Resolution Images” and issued in the name ofKuchta, et al., the disclosure of which is herein incorporated byreference. After images are captured, they can be quickly reviewed on acolor LCD image display 70 by using the thumbnail image data. Thegraphical user interface displayed on the color LCD image display 70 iscontrolled by the user controls 42.

In some embodiments of the present invention, the digital camera 10A isincluded as part of a camera phone. In such embodiments, the imageprocessor 50 also interfaces to a cellular processor 90, which uses acellular modem 92 to transmit digital images to a cellular network (notshown) using radio frequency transmissions via an antenna 94. In someembodiments of the present invention, the image capture assembly 1 maybe an integrated assembly including the lenses 2 and 3, the imagesensors 12 and 14, and zoom and focus motors 5 a. In addition, the clockdrivers 13 and 15, as well as the analog signal processors 22 and 24,the analog mux 34, and the A/D converter 36, may be part of theintegrated assembly.

FIGS. 2A and 2B show perspective views of the digital camera 10Adescribed in relation to FIG. 1. FIG. 2A is a frontal view of the camera10A, showing the fixed focal length lens 2, the zoom lens 3 and theflash 48. The fixed focal length lens is preferably an ultra wide anglelens; a suitable lens has a 22 mm equiv. focal length and an f/2 maximumaperture. The zoom lens is preferably an ultra-thin lens, e.g., a prismlens; a suitable zoom would be a 3:1 zoom ratio lens, such as a 38-114mm equiv. focal length zoom lens. A prism lens is a lens configuration,such as shown in FIGS. 16A, 16B, and 17, that incorporates a prism 8 a,8 b for folding the optical path, thereby creating a very compactoptical construction. Clearly, other lens focal lengths and lens typeconstructions are within the scope of the invention. FIG. 2B is a rearview of the camera 10A, showing the color (LCD) image display 70 and anumber of user controls 42, including a shutter button 42 a for enablingan image capture sequence, a panoramic button 42 b for enabling apanoramic mode, a zoom button 42 c for enabling a selection of a zoomsetting, and a multi-position selector 42 d for navigating throughimages, menu choices and the like that are displayed on the color LCDdisplay 70.

In a further embodiment, the aspect ratio of the image provided by thefixed focal length lens 2 and the image sensor 12 may be different thanthe aspect ratio of the image provided by the zoom lens 3 and the imagesensor 14. For example the image sensor 12 can have a 16:9 image aspectratio, with 2730 active columns of pixels×1536 active rows of pixels,for a total of 4.2 effective megapixels. Consequently, the display 70 ispreferably a wide aspect ratio (e.g., 16:9) format display. As shown inFIGS. 18A and 18B, the aspect ratio of the image sensor 12 (shown inbroken line) may represent a panoramic image 18 (e.g., a 16:9 aspectratio panoramic image as shown in FIG. 18A) and the aspect ratio of theimage sensor 14 (shown in broken line) may represent a typicaltelevision aspect ratio image 19 (e.g., a 4:3 aspect ratio image asshown in FIG. 18B). In this case, the user control 42 may input usercommands to the control processor and timing generator 40 for changingthe aspect ratio of the stored images which are provided by the imagesensor 12 in order to obtain a variable panoramic effect thattransitions from the wide angle of the lens 2 toward a narrower angleapproaching the effect of the 4:3 aspect ratio of the zoom lens 3. Thisis accomplished by cropping the image data which has been stored in DRAMbuffer memory 38, so that only a center subset of the image dataprovided from the image sensor 12 is processed by image processor 50 andstored on removable memory card 54. For example, and as shown in FIG.18A, the vertical margins 18 b of the image may be continuouslyadjusted, from the normal 16:9 aspect ratio to a wider aspect ratioimage, by pressing on the wide control section of the zoom button 42 c.In response, the top and bottom of the image in DRAM buffer memory 38 iscropped by image processor 50 to produce increasingly wider aspectratios, such as 17:9, 18:9 (2:1), 19:9, etc. image aspect ratios.Alternatively, the horizontal margins 18 a of the image may be adjusted,from the normal 16:9 aspect ratio to a narrower aspect ratio image byinstead pressing on the telephoto control section of the zoom button 42c. In response, the left and right sides of the image in DRAM buffermemory 38 are cropped by image processor 50 to produce increasinglynarrower aspect ratios, such as 15:9, 14:9, 3:2, etc. image aspectratios. In this manner, a variable panoramic effect may be digitallyeffected using the image data from the first image sensor 12.

FIG. 3 depicts a flow diagram showing a method for capturing digitalimages using the digital camera of FIG. 1. In lens setting block 100,when the camera 10A is turned on using a power switch (not shown), thezoom lens 3 is set to a default position, which is preferably a wideangle position (e.g., the 38 mm position). In panoramic decision block102, if the user presses the panoramic button 42 b (i.e., a yes responseto block 102), the control processor and timing generator 40 controlsthe analog multiplexer 34 to use (first sensor block 114) the output ofthe analog signal processor (ASP 1) 22, so that the output of the firstimage sensor 12 is provided to the A/D converter 36. Thereupon, apreview image from the image sensor 12 is captured and displayed inpreview block 116. If the zoom button is pressed at this point (havingspecified that the wide angle image is being used), the aspect ratio ofthe image is modified in the aspect ratio adjustment block 118 so as toobtain a variable panoramic effect from the wide angle of the lens 2.Then, if the shutter button is pressed, a still image is captured incapture block 120 using the output of the first sensor 12.

In panoramic decision block 102, if the user does not press thepanoramic button 42 b (i.e., a no response to block 102), the controlprocessor and timing generator 40 controls the analog multiplexer 34 touse (second sensor block 104) the output of the analog signal processor(ASP2) 24, so that the output of the second image sensor 14 is providedto A/D converter 36. Thereupon, a preview image from the image sensor 14is captured and displayed in preview block 106. If the zoom button ispressed at this point (having specified that the zoom image is beingused), the position of the zoom lens is adjusted in the zoom adjustmentblock 108 so as to obtain a zooming effect from the minimum focal lengthto the maximum focal length of the zoom lens 3. Then, if the shutterbutton is pressed, a still image is captured in capture block 110 usingthe output of the second sensor 14.

In a further variation on this embodiment, after the panoramic button 42b is pressed (having thus specified that the wide angle image is beingused) or if the zoom button 42 c is pressed without first pressing thepanoramic button 42 b (having thus specified that the zoom image isbeing used), the image sensor that is not being used may optionally bepowered down (in the power down block 112) to reduce the power drain andconserve the battery supply.

FIG. 4 depicts a block diagram of a digital camera 10A, which utilizesthe second embodiment of the present invention. In the secondembodiment, a digital camera 10B includes two zoom lenses, eachproviding an image to a corresponding image sensor. The first zoom lens3 is controlled by zoom and focus motors 5 a, and provides an image tothe first image sensor 14. The second zoom lens 4 is controlled by zoomand focus motors 5 b, and provides an image to the second image sensor16. A user zoom control on the camera selects, depending on its setting,either the output 14 e of the first image sensor 14 or the output 16 eof the second image sensor 16. The remaining aspects of the digitalcamera 10B are similar to the digital camera 10A shown in FIG. 1, andretain the same reference characters. Reference is therefore made toFIG. 1 for further description of these aspects of the digital camera10B.

FIGS. 5A and 5B show perspective views of the digital camera 10Bdescribed in relation to FIG. 4. FIG. 5A is a front view of the camera10B, showing the first zoom lens 3, the second zoom lens 4 and the flash48. The first zoom lens 3 is preferably an ultra-thin lens, e.g., aprism lens; a suitable zoom would be an approximately 3:1 zoom ratiolens, such as a 38-114 mm equiv. focal length zoom lens. The second zoomlens 4 is preferably another ultra-thin lens, e.g., a prism lens; asuitable zoom would be an approximately 3:1 zoom ratio lens, such as a133-380 mm equiv. focal length zoom lens. Preferably a total zoom ratioof approximately 10:1 may be obtained from the usage of both of the zoomlens. Furthermore, in a preferred embodiment, and since the motorizedzooming is typically done between discrete zoom steps rather thancontinuously, the small gap in focal length between first zoom lens 3and the second zoom lens 4 is equivalent to a focal length zoom step.Clearly, other lens focal lengths and lens type constructions are withinthe scope of the invention.

FIG. 5B is a rear view of the camera 10B, and similar in all respects,except for the lack of the panoramic button 42 b, to FIG. 2B. Sinceneither imager has a panoramic aspect ratio, the display 70 ispreferably a 4:3 aspect ratio display.

FIG. 6 depicts a flow diagram showing a method for capturing digitalimages using the digital camera of FIG. 4. In lens setting block 100,when the camera 10B is turned on using a power switch (not shown), thefirst zoom lens 3 is set to a default position, which is preferably awide angle position (e.g., the 38 mm position).

In zoom position block 122, if the user presses the zoom button 42 c andobtains a position beyond X (i.e., something greater than 125 mm andtherefore a yes response to block 122), the control processor and timinggenerator 40 controls the analog multiplexer 34 to use (second sensorblock 134) the output of the analog signal processor (ASP 1) 24, so thatthe output of the second image sensor 16 is provided to the A/Dconverter 36. Thereupon, a preview image from the image sensor 16 iscaptured and displayed in preview block 136. Then, if the shutter buttonis pressed, a still image is captured in capture block 140 using theoutput of the second sensor 16. If the zoom button is pressed at thispoint in the zoom button block 138, control is returned to the zoomposition block 122.

In zoom position block 122, if the user presses the zoom button 42 c andobtains a position less than a position X (i.e., something less than 125mm and therefore a no response to block 122), the control processor andtiming generator 40 controls the analog multiplexer 34 to use (firstsensor block 124) the output of the analog signal processor (ASP2) 22,so that the output of the first image sensor 14 is provided to the A/Dconverter 36. Thereupon, apreview image from the image sensor 14 iscaptured and displayed in preview block 126. Then, if the shutter button42 a is pressed, a still image is captured in capture block 130 usingthe output of the first sensor 16. If the zoom button is pressed at thispoint in the zoom button block 128, control is returned to the zoomposition block 122, and the process is repeated.

FIG. 7 depicts a block diagram of a digital camera 10C, which utilizesthe third embodiment of the present invention. In the third embodiment,a digital camera 10C includes two zoom lenses 3 and 4 and a fixed focallength lens 2, each providing an image to a corresponding image sensor.The first zoom lens 3 is controlled by zoom and focus motors 5 a, andprovides an image to the first image sensor 14. The second zoom lens 4is controlled by zoom and focus motors 5 b, and provides an image to thesecond image sensor 16. The fixed focal length lens 2 provides an imageto the third image sensor 12. A user zoom control on the camera selects,depending on its setting, either the output 14 e of the first imagesensor 14, the output 16 e of the second image sensor 16, or the output12 e of the third image sensor 12. The remaining aspects of the digitalcamera 10C are similar to the digital camera 10B shown in FIG. 4, andretain the same reference characters. Reference is therefore made toFIG. 4 for further description of these aspects of the digital camera10C.

FIGS. 8A and 8B show perspective views of the digital camera 10Cdescribed in relation to FIG. 7. FIG. 8A is a frontal view of the camera10C, showing the first zoom 3, the second zoom lens 4, the fixed focallength lens 2 and the flash 48. The first zoom lens 3 is preferably anultra-thin lens, e.g., a prism lens; a suitable zoom would be anapproximately 3:1 zoom ratio lens, such as a 38-114 mm equiv. focallength zoom lens. The second zoom lens 4 is preferably anotherultra-thin lens, e.g., a prism lens; a suitable zoom would be anapproximately 3:1 zoom ratio lens, such as a 133-380 mm equiv. focallength zoom lens. Preferably a total zoom ratio of approximately 10:1may be obtained from the usage of both of the zoom lens. Furthermore, ina preferred embodiment, the small gap in focal length between first zoomlens 3 and the second zoom lens 4 is equivalent to a focal length zoomstep. The fixed focal length lens is preferably an ultra wide anglelens; a suitable lens has a 22 mm equiv. focal length and an f/2 maximumaperture. Clearly, other lens focal lengths and lens type constructionsare within the scope of the invention.

FIG. 8B is a rear view of the camera 10C, and similar in all respects toFIG. 2B. In a further (optional) variation of the third embodiment, theaspect ratio (e.g., 16:9) of the image provided by the fixed focallength lens 2 may be different than the aspect ratio of the imageprovided by the zoom lenses 3 or 4. In this case, as was shown in FIG.2B, the user control 42 (e.g., the zoom button 42 c) may input usercommands for changing the aspect ratio of the image sensor 2 in order toobtain a variable panoramic effect that transitions from the wide angleof the lens 2 toward a narrower angle approaching the effect of the 4:3aspect ratio of the zoom lens 3.

FIG. 9 depicts a flow diagram showing a method for capturing digitalimages using the digital camera of FIG. 7. This figure is mostly acomposite of the blocks in FIGS. 3 and 6, and most of the blocks retainthe same reference characters for the same block functions and steps. Inlens setting block 100, when the camera 10B is turned on using a powerswitch (not shown), the first and second zoom lenses 3 and 4 are set todefault positions, which are preferably the wide angle position of eachlens (e.g., the 38 mm position for lens 3 and the 125 mm position forlens 4).

In panoramic decision block 102, if the user presses the panoramicbutton 42 b (i.e., a yes response to block 102), the control processorand timing generator 40 controls the analog multiplexer 34 to use (thirdsensor block 115) the output of the analog signal processor (ASP1) 26,so that the output of the third image sensor 12 is provided to the A/Dconverter 36. Thereupon, a preview image from the image sensor 12 iscaptured and displayed in preview block 116. If the zoom button ispressed at this point (having specified that the wide angle image isbeing used), the aspect ratio of the image is modified in the aspectratio adjustment block 118 so as to obtain a variable panoramic effectfrom the wide angle of the lens 2. Then, if the shutter button ispressed, a still image is captured in capture block 120 using the outputof the third sensor 12.

If the panoramic decision block 102 is not engaged (i.e., the user hasnot pressed the panoramic button 42 b), control is transferred to thezoom position block 122. In zoom position block 122, if the user pressesthe zoom button 42 c and obtains a position beyond X (i.e., somethinggreater than 125 mm and therefore a yes response to block 122), thecontrol processor and timing generator 40 controls the analogmultiplexer 34 to use (second sensor block 134) the output of the analogsignal processor (ASP1) 24, so that the output of the second imagesensor 16 is provided to the A/D converter 36. Thereupon, a previewimage from the image sensor 16 is captured and displayed in previewblock 136. Then, if the shutter button is pressed, a still image iscaptured in capture block 140 using the output of the second sensor 16.If the zoom button is pressed at this point in the zoom button block138, control is returned to the zoom position block 122.

In zoom position block 122, if the user presses the zoom button 42 c andobtains a position less than a position X (i.e., something less than 125mm and therefore a no response to block 122), the control processor andtiming generator 40 controls the analog multiplexer 34 to use (firstsensor block 124) the output of the analog signal processor (ASP2) 27,so that the output of the first image sensor 14 is provided to the A/Dconverter 36. Thereupon, a preview image from the image sensor 14 iscaptured and displayed in preview block 126. Then, if the shutter button42 a is pressed, a still image is captured in capture block 130 usingthe output of the first sensor 16. If the zoom button is pressed at thispoint in the zoom button block 128, control is returned to the zoomposition block 122, and the process is repeated.

FIG. 19 represents the fourth and fifth embodiments of the invention,where a digital camera 10D includes two (the fourth embodiment) fixedfocal length lenses or a digital camera 10E includes three (the fifthembodiment) fixed focal length lenses, each providing an image to acorresponding imaging array. FIG. 19 specifically depicts a blockdiagram of a digital camera 10E according to the fifth embodiment of thepresent invention. In the fifth embodiment, a digital camera 10Eincludes three fixed focal length lens, each providing an image to acorresponding image sensor. The first fixed focal length lens 2 aprovides an image to the first image sensor 12 a. The second fixed focallength lens 2 b provides an image to the second image sensor 12 b. Thethird fixed focal length lens 2 c provides an image to the third imagesensor 12 c. A user zoom control on the camera selects, depending on itssetting, either the output of the first image sensor 12 a, the output ofthe second image sensor 12 b, or the output of the third image sensor 12c. More specifically, the user zoom control on the camera selects eitherthe output of one of the three image sensors to provide a roughmagnification setting, and in addition uses a digital zoom provided bythe image processor 50 to provide fine magnification control. Forexample, the first focal length lens 2 a may have a focal length of 30mm equiv. (35 mm equivalent), the second fixed focal length 2 b lens mayhave a focal length of 90 mm equiv., and the third fixed focal lengthlens 2 c may have a focal length of 135 mm equiv. The zoom lens controlmay provide settings from 30 mm to 270 mm. When the user selects 60 mm,for example, the output from the first sensor 12 a is selected, alongwith a 2× digital zoom. When the user selects 270 mm, the output of thethird sensor 12 c is selected, along with 2× digital zoom.

In the fourth embodiment, a digital camera 10D includes two fixed focallength lens, each providing an image to a corresponding image sensor.Consequently, for the fourth embodiment, FIG. 19 is modified such thatthe third fixed focal length lens 2 c, and its ancillary components andcircuitry, is eliminated. A user zoom control on the camera selects,depending on its setting, either the output of the first image sensor 12a, or the output of the second image sensor 12 b. For example, the firstfocal length lens 2 a may have a focal length of 30 mm equiv. (35 mmequivalent), and the second fixed focal length 2 b lens may have a focallength of 90 mm equiv. The zoom lens control 42 c may provide settingsfrom 30 mm to 270 mm. When the user selects 60 mm, for example, theoutput from the first sensor 12 a is selected, along with a 2× digitalzoom. When the user selects 270 mm, the output of the second sensor 12 bis selected, along with 3× digital zoom. The remaining aspects of thedigital cameras 10D and 10E are similar to the digital camera 10B shownin FIG. 4, and retain the same reference characters. Reference istherefore made to FIG. 4 for further description of these aspects of thedigital cameras 10D and 10E.

The perspective views of digital cameras 10D and 10E are not shown, asthey are substantially similar to the perspective views of FIGS. 5A and5B, except that another optical relay subassembly is included for thedigital camera 10E.

FIG. 20 depicts a flow diagram showing a method for capturing digitalimages using the digital camera 10E of FIG. 20. In a power up block 300,the camera 10E is turned on using a power switch (not shown). In zoomposition block 302, if the user presses the zoom button 42 c and obtainsa position beyond X (e.g., something equal to or greater than 90 mmequiv. and therefore a yes response to block 302), control istransferred to the second zoom position block 314. There, if the zoombutton 42 c is indicating a position beyond Y (e.g., something equal toor greater than 135 mm equiv. and therefore a yes response to block314), the control processor and timing generator 40 controls the analogmultiplexer 34 to use (third sensor block 318) the output of the analogsignal processor (ASP3) 26, so that the output of the third image sensor12 c is provided to the A/D converter 36. If the zoom control 42 c isrequesting a focal length other than the optical 135 mm equiv., digitalzoom is applied to the image in the zoom block 306 to bring the image upto the requested focal length. Thereupon, a preview image from the imagesensor 12 c is captured and displayed in preview block 308. Then, if theshutter button is pressed, a still image is captured in capture block312 using the output of the third sensor 12 c. If the zoom button ispressed at this point in the zoom button block 310, control is insteadreturned to the zoom position block 302.

If the zoom button 42 c is indicating a position less than Y (i.e.,something less than 135 mm equiv. and therefore a no response to block314), the control processor and timing generator 40 controls the analogmultiplexer 34 to use (second sensor block 316) the output of the analogsignal processor (ASP2) 24, so that the output of the second imagesensor 12 b is provided to the A/D converter 36. If the zoom control 42c is requesting a focal length other than the optical 90 mm equiv.,digital zoom is applied to the image in the zoom block 306 to bring theimage up to the requested focal length. Thereupon, a preview image fromthe image sensor 12 b is captured and displayed in preview block 308.Then, if the shutter button is pressed, a still image is captured incapture block 312 using the output of the second sensor 12 b. If thezoom button is pressed at this point in the zoom button block 310,control is instead returned to the zoom position block 302.

In zoom position block 302, if the user presses the zoom button 42 c andobtains a position less than a position X (i.e., something less than 90and therefore a no response to block 302), the control processor andtiming generator 40 controls the analog multiplexer 34 to use (firstsensor block 304) the output of the analog signal processor (ASP1) 22,so that the output of the first image sensor 12 a is provided to the A/Dconverter 36. If the zoom control 42 c is requesting a focal lengthother than the optical 30 mm equiv., digital zoom is applied to theimage in the zoom block 306 to bring the image up to the requested focallength. Thereupon, a preview image from the image sensor 12 a iscaptured and displayed in preview block 308. Then, if the shutter button42 a is pressed, a still image is captured in capture block 312 usingthe output of the first sensor 12 a. If the zoom button is pressed atthis point in the zoom button block 310, control is returned to the zoomposition block 302, and the process is repeated.

A number of advantages may be obtained by use of the fixed focal lengthlenses in the fourth and fifth embodiments. The aperture of each lenscan be kept quite large (e.g., f/2.8 at least for the widest anglelens), thereby providing a high speed, low light lens. In addition, theimage quality can be kept higher than for a comparable zoom lens. Whendigital zooming is employed, there are no moving parts for the zoom—eventhough there are two (or three) optical settings—and the zoom iscompletely silent and relatively fast in zoom focal length transitions.

In the sixth embodiment (which is not shown as a separate blockdiagram), a digital camera 10F includes four fixed focal length lenses,each providing an image to a corresponding image sensor. Consequently,for the sixth embodiment, FIG. 19 is modified such that a fourth fixedfocal length lens 2 d, and its ancillary components and circuitry, isadded. A user zoom control on the camera selects, depending on itssetting, either the output of the first image sensor 12 a, the output ofthe second image sensor 12 b, the output of the third sensor 12 c, orthe output of the fourth sensor 12 d. For example, the first focallength lens 2 a may have a focal length of 30 mm equiv. (35 mmequivalent), and the second fixed focal length 2 b lens may have a focallength of 60 mm equiv., the third fixed focal length 2 b lens may have afocal length of 120 mm equiv., and the fourth fixed focal length 2 blens may have a focal length of 270 mm equiv. The zoom lens control 42 cmay provide settings from 30 mm to 400 mm. When the user selects 45 mm,for example, the output from the first sensor 12 a is selected, alongwith a 1.5× digital zoom. When the user selects 90 mm, for example, theoutput from the second sensor 12 b is selected, along with a 1.5×digital zoom. When the user selects 240 mm, for example, the output fromthe third sensor 12 c is selected, along with a 2× digital zoom. Whenthe user selects 400 mm, the output of the fourth sensor 12 d isselected, along with 1.5× digital zoom. The remaining aspects of thedigital camera 10F are similar to the digital camera 10E shown in FIG.19, and reference is therefore made to FIG. 19 for further descriptionof these aspects of the digital camera. The perspective views and flowdiagram of the digital camera 10F are not shown, as they aresubstantially similar to the perspective views of FIGS. 5A and 5B andthe flow diagram of FIG. 20, except that yet another optical relaysubassembly, and another flow column in FIG. 20 for the fourth sensor 12c, is included for the digital camera 10F.

In many of the foregoing embodiments, digital zooming is used. Digitalzooming is a well-known process and any of a variety of techniques maybe used. One such digital zooming capability is described incommonly-assigned pending U.S. Patent Application Publication No.2003/0202113, “Electronic Still Camera and Image Processing Method”filed on Aug. 1, 2002 in the name of Sumito Yoshikawa and which isincorporated herein by reference. For the type of system disclosed inthis pending patent application, as well as for the system according tothe present invention, the image sensor includes an array of discretelight sensitive picture elements overlaid with a color filter array(CFA) pattern to produce color image data corresponding to the CFApattern. The output data from the image sensor is applied to an analogsignal processing (ASP) and analog/digital (A/D) conversion section,which produces digital CFA data from the color image data.

The resultant digital data is applied to a digital signal processor,such as the image processor 50 (referring to FIG. 1 of the presentdisclosure), which interpolates red, green, and blue (RGB) color imagedata for all of the pixels of the color image sensor. The CFA image datarepresents an image of a fixed size, such as 2048 columns of pixels×1536rows of pixels. A digitally zoomed image is provided by taking thecenter section of the CFA image data and interpolating additional pixelsthat fall in between the pixels provided by the image sensor. Forexample, a 2:1 digital zoom is provided by using only the center 1024columns×768 rows of the CFA image data, and by interpolating oneadditional row and column in between each of the rows and columns of thecenter CFA image data, so as to enlarge the center of the image. Theoutput of the image processor 50 is a color interpolated and digitallyzoomed image, with 2048 columns and 1536 rows of RGB data, provided fromthe center 1024 columns×768 rows of CFA image data.

In operation of the present imaging system according to theaforementioned Yoshikawa patent disclosure, the user operates thedigital camera, e.g., the digital camera 10E (FIG. 19), to take pictureswhile observing the image on the color LCD image display 70. The digitalCFA image for each of the captured images is processed by the imageprocessor 50 and displayed in a “thumbnail” or subsampled format in thepreview step (e.g., steps 308 in FIG. 20). If the observed zoom amountis not desired, the user then changes the zooming/cropping setting in azoom selection/cropping step (e.g., steps 302, 314 in FIG. 20) by usingthe zoom button 42 c. The amount of digital zooming is determined by thecontrol processor and timing generator 40 and provided to the imageprocessor 50. The control processor and timing generator 40 selectswhich of the image sensor outputs to use (by controlling the analog mux34), and the amount of digital zoom needed, which in combination providethe desired overall zoom setting. For example, a 2.5:1 overall zoomsetting can be provided by selecting (using the analog mux 34) a lensand image sensor that provides a 2:1 optical zoom and also instructingthe image processor 50 to provide a 5:4 digital zoom setting, which usesthe center 1638 columns×1230 rows (from the 2048 columns×1536 rows ofCFA image data).

In an additional embodiment shown in FIG. 21, the two (or three) lenseshave identical focal lengths, and the imaging arrays are different sizes(e.g. both sensors are, e.g., 3.1 effective megapixel sensors with 2048columns×1536 rows of pixels, but the first image sensor 412 a has 3.1micron square pixels and the second image sensor 412 b has 6.2 micronsquare pixels, so that the diagonal of the second image sensor is twiceas large as the first image sensor). With the differently sized imagingarrays, each lens is designed to fill the area of the imaging array andeach lens-array combination can have substantially the same actual focallength, i.e., the same lens to array distance. However, the 35 mm equiv.of each lens will be different, in proportion to the difference in thediagonal size of the array; consequently, each lens will have adifferent field of view. In FIG. 21, in this additional embodiment, adigital camera 10G includes a first fixed focal length lens 402 a thatprovides an image to a first image sensor 412 a, which has 3.1 micronpixels. A second fixed focal length lens 402 b provides an image to asecond image sensor 412 b, which has 6.2 micron pixels. A user zoomcontrol 42 on the camera selects, depending on its setting, either theoutput of the first image sensor 412 a or the output of the second imagesensor 412 b. More specifically, the user zoom control on the cameraselects the output of one of the two image sensors to provide a roughmagnification setting based on the 35 mm equiv. focal length of thelenses 402 a and 402 b, and in addition uses a digital zoom provided bythe image processor 50 to provide fine magnification control. Forexample, the first focal length lens 402 a may have an actual focallength of 16 mm, which provides a 35 mm equiv. focal length of about 80mm because the pixels are 3.1 mm so that the diagonal size is about 8mm. The second fixed focal length 402 b lens may also have an actualfocal length of 16 mm, but it provides a 35 mm equivalent focal lengthof about 40 mm, because the pixels are 6.2 mm so that the diagonal sizeis about 16 mm. The zoom lens control may provide settings from 40 mm to160 mm. When the user selects 60 mm, for example, the output from thesecond sensor 412 b is selected, along with a 1.5× digital zoom. Whenthe user selects 160 mm, for example, the output of the first sensor 412a is selected, along with 2× digital zoom.

The remaining aspects of the digital cameras 10G are similar to thedigital camera 10B shown in FIG. 4, and retain the same referencecharacters. Reference is therefore made to FIG. 4 for furtherdescription of these aspects of the digital camera 10G.

A further advantage of the invention is that use of dual zooms providesan extended optical zoom range in a digital camera where the movementbetween user-requested zoom positions may be undertaken in an expeditedmanner. Since motorized zooming is typically done between discrete zoomsteps rather than continuously, the full range of a zoom system isdivided into a finite number of discrete steps. For example, as shown inFIG. 22, a two zoom system in accordance with the invention may bedivided into a first zoom range 500 providing a 38 mm-114 mm equiv. zoomlens range and a second zoom range 502 providing a 133 mm-380 mm equiv.zoom lens range Such an arrangement may be provided by the digitalcamera 10B shown in FIG. 4. According to this arrangement, the zoom andfocus motors 5 a and 5 b drive the respective zoom lenses 3 and 4through a finite series of discrete steps, where each step represents,for the example shown in FIG. 22, 0.5× zoom steps over the lower zoomrange, and 1× zoom steps over the higher zoom range More particularly,the zoom and focus motor 5 a drives the zoom lens 3 from 38 mm to 114 mmin five discrete steps, with the steps corresponding to 1× (38 mm), 1.5×(57 mm), 2× (76 mm), 2.5× (95 mm) and 3× (114 mm) zoom steps. The zoomand focus motor 5 b drives the zoom lens 4 from 133 mm to 380 mm inseven discrete steps, with the steps corresponding to 3.5× (133 mm), 4×(152 mm), 5× (190 mm), 6× (228 mm), 7× (266 mm), 8× (304 mm), 9× (342mm), and 10× (380 mm) zoom steps. The two lenses are separated in focallength by a one step gap 503 (i.e., by 19 mm, corresponding to the 0.5×gap between the 3× zoom focal length and the 3.5× zoom focal length.).

In operation, the user operates the user control 42 in order to select azoom setting, whereby the zoom and focus motors 5 a and 5 b areresponsive to the user control 42 for adjusting the zoom lenses throughthe first plurality of discrete zoom positions 500 for the first zoomlens 3 and through the second plurality 502 of discrete zoom positionsfor the second zoom lens 4. The control processor and timing generator40, acting as a zoom controller, controls the zoom and focus motors 5 aand 5 b and enables an express mode when a user initiated change in theuser control specifies a zoom transition from a present zoom settingwithin one of the plurality of discrete zoom positions in one of theranges to a target zoom setting within the other plurality of discretezoom positions in the other range. The control processor and timinggenerator 40 causes the zoom and focus motor of the lens containing thetarget position to immediately move the corresponding zoom lens to thetarget zoom position without powering the other zoom and position motorthrough any intervening discrete zoom positions, thereby enabling anexpress zooming sequence in which the zoom and focus motors of the lensnot containing the target position do not have to traverse all of theintervening zoom positions between the present zoom setting and thetarget zoom setting.

An example is shown in FIG. 22. In the power up mode, both zoom lenseswill be brought to their minimum focal length positions, i.e., the zoomlens 3 will be driven to the 38 mm position and the zoom lens 4 will bedriven to the 133 mm position. If the user initially chooses to view asubject at the widest angle position, say 38 mm equiv., the zoom lens 3will provide its widest angle image to the image sensor 14 (FIG. 4) andthe analog multiplexer 34 will select the first image output 14 e fromthe first image sensor 14. If the user then presses the zoom button 42 cto a tele position, say 228 mm equiv., the usual response in a singlezoom lens that spanned the range from 38 mm to 228 mm would be to drivethe zoom lens through an 8 step sequence 504 as shown in FIG. 22.However, in the express mode according to the invention, the controlprocessor and timing generator 40 immediately directs the zoom and focusmotor 5 b to drive the lens 4 through a 3 step sequence 506 from 133 mmto 228 mm. Meanwhile, the zoom lens 3 remains at its widest setting.Consequently, five steps of movement are saved and the movement betweenuser-requested zoom positions is undertaken in an expedited mannercompared to the prior art situations. Clearly, FIG. 22 is only anexample, and many other variations of step length and zoom ranges arewithin the scope of the invention. For example, in power up mode, thelens 4 could be set to the maximum focal length (380 mm) rather than thewidest focal length (133 mm). Then the camera could be immediatelyswitched from the wide-angle position (38 mm equiv.) to the maximumtelephoto position (380 mm equiv.) immediately, simply by switching theanalog mux 34 to provide the output of the 2^(nd) image sensor 16.

The concept of multiple lenses and multiple sensors, and the use of anintegrated image capture assembly, may be adapted for use in a cellphone of the type having a picture taking capability. Accordingly, andas shown in FIG. 23A, a cell phone 600 includes a phone stage comprisinga microphone 602 for capturing the voice of a caller, relatedelectronics (not shown) for processing the voice signals of the callerand the person called, and a speaker 604 for reproducing the voice ofthe one called. A keypad 606 is provided for entering phone numbers andimage capture commands, and a (LCD) display 608 for showingphone-related data and for reproducing images captured by the phone orreceived over the cellular network. The rear view of the cell phone 600shown in FIG. 23B identifies some of the internal components, includinga cellular image capture assembly 610 connected via the image processor50 (as shown in FIG. 1) to a cellular processing stage comprising thecellular processor 90 and the modem 92. The cellular processor 90receives and processes the image data from the image processor 50 andthe voice data captured by the microphone 602, and transfers the imageand voice data to the cellular modem 92. The cellular modem 92 convertsthe digital image and voice data into the appropriate format fortransmission by the antenna 94 to a cellular network.

As the cellular image capture assembly 610 is shown in FIGS. 24A and24B, where FIG. 24B is a top view of the assembly 610 taken along thelines 24B-24B in FIG. 24A, the assembly 610 comprises an integratedpackaging of the optical and imaging components on a common substrate620. More specifically, the assembly 610 includes a first fixed focallength lens 612 and a first image sensor 614, and a second fixed focallength lens 616 and a second image sensor 618. The first lens 612,preferably a fixed focal length wide angle lens (such as a 40 mm equiv.lens), forms an image on the first image sensor 614, and the second lens616, preferably a fixed focal length telephoto lens (such as 100 mmequiv. lens), forms an image on the second image sensor 618. Both of thelenses are oriented in the same direction in order to form images of thesame portion of the overall scene in front of them, albeit withdifferent fields of view.

Each lens 612 and 616 and each associated image sensor 614 and 618 aremounted to the substrate 620 with an IR cut filter in between to reducethe incidence of IR radiation on the image pixels. Electronic components624, such as resistors, capacitors and power management components, arealso mounted on the substrate 620. The image signals are taken from thesubstrate 620 via a flex connector 626. The data taken from the assembly610 may be raw image data, or if suitable processors (not shown) are onboard the substrate 620, the data could be YUV image data or JPEG imagedata. Moreover, the image processor 50 may provide digital zoomingbetween the wide angle and the telephoto focal lengths; the user mayinitiate such zooming via a user interface displayed on the (LCD)display 608 and by keying appropriate buttons on the keypad 606.Furthermore, the wide angle image sensor 614 may have high resolution,e.g., higher than that of the telephoto image sensor 618, in order toprovide a higher quality source image for the digital zooming.

In one embodiment, the wide angle lens 612 is set to its hyperfocaldistance, which means it is in focus from a few feet to infinity withoutneed for any focus adjustment by the user. The telephoto lens 616 isautomatically focused by an auto focus subsystem 628. This is requiredbecause the hyperfocal distance increases as the focal length increases,and so the focus needs to be adjusted in order to obtain proper focusfor objects at typical (e.g. 4′ to 12′) distances. By using only onefocusing subsystem 628 for the telephoto lens 616, the cost and size canbe reduced.

An important constraint in this embodiment is the “z” dimension 630,which must be held to a very small figure consistent with a cell phonelayout and architecture. This may be obtained by careful choice of thetelephoto focal length and the size of the sensor. For example, the sizeof the sensor 616, and consequently the size of the image that must beproduced to fill the sensor, may be made small enough to reduce thefocal length to an acceptable z dimension 630.

In a further embodiment, as discussed in connection with FIG. 21, thetwo lenses may have approximately identical focal lengths, with theimaging arrays being of different sizes. With the differently sizedimaging arrays, each lens is designed to fill the area of the imagingarray and each lens-array combination will have substantially the sameactual focal length, i.e., the same lens to array distance. However, the35 mm equiv. of each lens will be different; consequently, each lenswill have a different field of view.

While not shown in detail in FIGS. 24A and 24B, but similarly as wasexplained in connection with FIG. 1, an analog output signal from thefirst image sensor 614 is amplified by a first analog signal processorand provided to a first input of a control element, e.g., an analogmultiplexer control element provided as one of the electronic components624 on the substrate 620. The analog output signal from the second imagesensor 618 is amplified by a second analog signal processor and providedto a second input of the control element. The function of the controlelement is to select either the first sensor output from the first imagesensor 614 or the second sensor output from the second image sensor 618,depending on user input from the keypad 606 as to zoom selection,thereby providing a selected sensor output from the cellular imagecapture assembly 600 to the image processor 50.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

PARTS LIST

-   1 image capture assembly-   1 a optical relay subassembly-   1 b optical relay subassembly-   1 c optical relay subassembly-   1 a(1) first optical relay subassembly-   1 a(2) second optical relay subassembly-   1 a(3) third optical relay subassembly-   1 a(4) fourth optical relay subassembly-   1 d front optical profile of the camera-   2 fixed focal length lens-   2 a first fixed focal length lens-   2 b second fixed focal length lens-   2 c third fixed focal length lens-   2 d fourth fixed focal length lens-   2 e first image sensor output-   3 first zoom lens-   4 (second) zoom lens-   5 a zoom and focus motors-   5 b zoom and focus motors-   5 c connecting gear train-   6 a lens barrel-   6 b fixture-   7 a relay lens components-   7 b movable relay (zoom) lens components-   8 a mirror prism-   8 b mirror prism-   9 a aperture shutter assembly-   9 b aperture shutter assembly-   10A digital camera (first embodiment)-   10B digital camera (second embodiment)-   10C digital camera (third embodiment)-   10D digital camera (fourth embodiment)-   10E digital camera (fifth embodiment)-   10F digital camera (sixth embodiment)-   10G digital camera (seventh embodiment)-   12 first image sensor-   12 a first image sensor-   12 b second image sensor-   12 c third image sensor-   12 d fourth image sensor-   12 e first image output-   13 clock drivers-   14 second image sensor-   14 e second image output-   15 clock drivers-   16 third image sensor-   16 e third image output-   17 clock drivers-   18 16:9 aspect ratio panoramic image-   18 a horizontal margin-   18 b vertical margin-   19 4:3 aspect ratio image-   22 first analog signal processor (ASP1)-   24 second analog signal processor (ASP2)-   26 third analog signal processor (ASP3)-   34 control element (analog multiplexer)-   36 analog-to-digital converter-   38 DRAM buffer memory-   40 control processor and timing generator-   42 user controls-   42 a shutter button-   42 b panoramic button-   42 c zoom button-   42 d multi-position selector-   46 automatic focus and automatic exposure detectors-   48 electronic flash-   50 image processor-   52 memory card interface-   54 removable memory card-   56 RAM memory-   58 firmware memory-   62 host interface-   64 interconnection-   66 host PC-   70 color LCD image display-   90 cellular processor-   92 cellular modem-   94 antenna-   100 lens setting block-   102 panoramic decision block-   104 second sensor block-   106 preview block-   108 zoom adjustment block-   110 capture block-   112 power down block-   114 first sensor block-   115 third sensor block-   116 preview block-   118 aspect ratio adjustment block-   120 capture block-   122 zoom position block-   124 first sensor block-   126 preview block-   128 zoom button block-   130 capture block-   134 second sensor block-   136 preview block-   138 zoom button block-   140 capture block-   201 width-wise dimension-   204 battery-   210 front to rear dimension-   300 power up block-   302 zoom position X block-   304 first sensor block-   306 digital zoom block-   308 preview block-   310 zoom button block-   312 capture block-   314 zoom position Y block-   316 second sensor block-   318 third sensor block-   320 removed section-   322 yes response-   402 a first lens-   402 b second lens-   412 a first (smaller) sensor-   412 b second (larger) sensor-   500 first zoom range-   502 second zoom range-   503 one step gap-   504 17 step zoom sequence-   506 9 step zoom sequence-   600 cell phone-   602 microphone-   604 speaker-   606 keypad-   608 (LCD) display-   610 cellular image capture assembly-   612 first fixed focal length lens-   614 first image sensor-   616 second fixed focal length lens-   618 second image sensor-   620 substrate-   622 IR cut filter-   624 electronic components-   626 flex connector-   628 auto focus subsystem-   630 z dimension

1. An optical image capture assembly for use in an electronic camera,said assembly comprising: a first image sensor for generating a firstsensor output; a first lens for forming a first image of the scene onthe first image sensor; a second image sensor for generating a secondsensor output; and a zoom lens pointing in the same direction as thefirst lens and forming a second image of the scene on the second imagesensor, wherein the zoom lens is adjustable between a minimum focallength and a maximum focal length to provide the second image.
 2. Theassembly as claimed in claim 1 further including a control section fordriving the sensors and for selecting either the first sensor outputfrom the first image sensor or the second sensor output from the secondimage sensor.
 3. The assembly as claimed in claim 1 wherein the firstlens has a fixed focal length.
 4. The assembly as claimed in claim 1wherein the first lens is an additional zoom lens.
 5. The assembly asclaimed in claim 1 further comprising: a plurality of additional imagesensors for generating a corresponding plurality of additional sensoroutputs; and a plurality of additional lenses for forming acorresponding plurality of additional images of the scene on theplurality of additional image sensors.
 6. The assembly as claimed inclaim 5 wherein at least one of the additional lenses is a zoom lens. 7.The assembly as claimed in claim 1 wherein the sensors are packaged in acommon integrated circuit package.
 8. The assembly as claimed in claim 7wherein the lenses are provided in a common assembly that mounts ontothe integrated circuit package.
 9. The assembly as claimed in claim 1wherein the camera is contained within an enclosure and at least one ofthe first lens and the zoom lens forms its image through a foldedoptical system in which an optical path between the lens and itsrespective image sensor is folded at an angle in order to conserve spacewithin the enclosure.
 10. The assembly as claimed in claim 1 wherein atleast one of the first lens and the zoom lens is a prism lens.